Ring Gear Tooth Quantity: 157-tooth Crankshaft to Flywheel Bolt Quantity: 6-bolt Pressure Plate Style: Diaphragm Rear Main Seal Style: 1-piece Flywheel Diameter: 13.280 in. Flywheel Material: Nodular iron Engine Balance: External 50oz Replaceable Friction Surface: No Marine Use: No Quantity: Sold individually. Notes: 13 1/4 inch diameter ring gear. With dowel pin holes. 50 oz. balance.